The long-term goal of the principal investigator?s research is to elucidate the interactions between the mosquito vector and Zika virus (ZIKV) and Dengue virus (DENV), to identify transmission-blocking targets suitable for the development of disease control strategies. During their journey through the vector, the viruses engage in intimate interactions with the mosquito midgut and other tissues, relying on numerous mosquito-derived agonists (host factors). ZIKV and DENV can be impaired in the vector by agonist deletion through gene editing, depletion through RNA interference, or blocking / interference / inhibition through antibodies. Hence, an obvious advantage of studying virus agonists for disease control is that they can be targeted through multiple means. The recently developed CRISPR/CAS9-based gene editing in Aedes mosquitoes provide new and promising opportunities for the study of agonist function through gene deletion, and could be used to develop novel ZIKV and DENV control strategies. Here we will focus on 10 virus agonists to assess their potential for disease control and further our knowledge of their involvement in ZIKV and DENV infection. In Aim 1, we will validate 6 putative DENV agonists for ZIKV blocking potential in Ae. aegypti using RNAi-mediated gene silencing. In Aim 2, we will develop CRISPR/CAS9-mediated conditional bloodmeal-inducible midgut-specific gene KO mosquitoes for selected ZIKV and DENV agonists. In Aim 3, we will assess these KO Ae. aegypti lines for resistance to virus infection and their fitness impact in terms of mosquito longevity and fecundity.